1 files changed, 100 insertions, 0 deletions
diff --git a/src/main/java/makamys/neodymium/util/virtualjar/VirtualJar.java b/src/main/java/makamys/neodymium/util/virtualjar/VirtualJar.java
new file mode 100644
index 0000000..8350d6f
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+++ b/src/main/java/makamys/neodymium/util/virtualjar/VirtualJar.java
@@ -0,0 +1,100 @@
+package makamys.neodymium.util.virtualjar;
+
+import static makamys.neodymium.Constants.MODID;
+import static makamys.neodymium.Constants.PROTOCOL;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.util.HashMap;
+import java.util.Map;
+
+import static makamys.neodymium.Constants.LOGGER;
+
+import makamys.neodymium.util.virtualjar.protocol.neodymiumvirtualjar.Handler;
+import net.minecraft.launchwrapper.Launch;
+
+
+public class VirtualJar {
+    
+    private static boolean registered;
+    
+    private static Map<String, IVirtualJar> jars = new HashMap<>();
+    
+    public static void registerHandler() {
+        if(registered) return;
+        
+        LOGGER.debug("Registering URL protocol handler: " + PROTOCOL);
+        
+        // We want the Handler to always be loaded by the same class loader.
+        Launch.classLoader.addClassLoaderExclusion("makamys." + MODID + ".util.virtualjar.protocol." + PROTOCOL);
+        
+        // The Handler is loaded by the AppClassLoader, but it needs to access the state of VirtualJar, which is loaded
+        // by the LaunchClassLoader. The solution? Make the Handler just a proxy that delegates the real work to
+        // VirtualJar.StreamHandlerImpl. We use the blackboard as a class loader-agnostic way of sharing information.
+        Handler.IURLStreamHandlerImpl streamHandlerImpl = new StreamHandlerImpl();
+        Launch.blackboard.put(MODID + "." + PROTOCOL + ".impl", streamHandlerImpl);
+        URLStreamHandlerHelper.register(Handler.class);
+        
+        registered = true;
+    }
+    
+    public static void add(IVirtualJar jar) {
+        registerHandler();
+        
+        LOGGER.trace("Adding virtual jar to class path: " + PROTOCOL + ":" + jar.getName() + ".jar");
+        
+        String urlStr = PROTOCOL + ":" + jar.getName() + ".jar!/";
+        
+        try {
+            URL url = new URL(urlStr);
+            Launch.classLoader.addURL(url);
+            // Forge expects all URLs in the sources list to be convertible to File objects, so we must remove it to
+            // avoid a crash.
+            Launch.classLoader.getSources().remove(url);
+            
+            jars.put(jar.getName(), jar);
+        } catch(MalformedURLException e) {
+            LOGGER.fatal("Failed to add virtual jar to class path");
+            e.printStackTrace();
+        }
+    }
+    
+    public static class StreamHandlerImpl implements Handler.IURLStreamHandlerImpl {
+
+        @Override
+        public URLConnection openConnection(URL url) {
+            return new URLConnection(url) {
+                public void connect() {
+                    
+                }
+
+                public Object getContent() throws IOException {
+                    return super.getContent();
+                }
+
+                public String getHeaderField(String name) {
+                    return super.getHeaderField(name);
+                }
+
+                public InputStream getInputStream() {
+                    String path = getURL().getPath();
+                    String nameSuffix = ".jar!";
+                    int nameEnd = path.indexOf(nameSuffix);
+                    String name = path.substring(0, nameEnd);
+                    
+                    IVirtualJar jar = jars.get(name);
+                    
+                    return jar.getInputStream(path.substring(nameEnd + nameSuffix.length()));
+                }
+
+                public java.io.OutputStream getOutputStream() throws IOException {
+                    return super.getOutputStream();
+                }
+            };
+        }
+    }
+    
+}